[Bug libstdc++/121245] __any_input_iterator should not accept C++20 input_iterator

[ppalka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121245

--- Comment #2 from Patrick Palka <ppalka at gcc dot gnu.org> ---
Note this relaxation only applies to container member functions.

InputIterator template parameter for _algorithms_ must be C++17 iterator as per
https://wg21.link/algorithms.requirements#4.2